James Lockman's Technical Blog

Posts tagged "XRite"

A friend of mine, Margie Dana, runs a group called Boston Print Buyers. On occasion, she forwards questions from members. Here’s one that I thought I should share.

Recently we had 2 incidents where our designers’ monitor did not match ours or the vendor’s proof. This was discovered at the proofing stage of our printing process. The proof obviously did not meet the expectation of our designer since it did not match their monitor. With that said, I have been assigned the task of finding out more about calibrating our monitors so we are all looking at the same thing.

Can you answer the questions below or point us in the right direction of finding a source that can help us?

Should we have our Mac monitors color calibrated?

If so, how often?

Is there a preferred method across the industry?

We do have technical support for our Macs. Should we let them do it or is this something we can do ourselves?

You’ve cracked a complex issue here. It’s not just the monitors, it’s the entire proofing workflow. In short, each stage of the proofing process, from scanner/camera to monitor to proof to press needs to be in sync. This happens through two mechanisms: linearization and characterization.

Linearization is the process where we ensure that a press or proofing device gives us what we expect. Our RIP will have a lookup table that says something like: when you ask for 30% cyan in my file, I need to put down 33% cyan on my plate because the press is off a little bit and we’ll compensate.” OK, it’s really a matrix of numbers without personality, but you get the idea. The RIP looks in the table to see how it should adjust each color in order to get output that matches the expectation.

Characterization is the process of determining what happens when we ask a device to produce a certain color. For instance, if I ask my monitor (an RGB device) to produce a CMYK mix of (2,57,33,5), what happens. Using this information about devices, I can make color transformations that allow me to simulate one color and how it will appear on a specific device on a completely different device. We encapsulate characterization in ICC profiles.

Now, let’s make this into a proofing workflow.

First off, not everyone linearizes. While I’d recommend it as a best practice for any printer, they don’t all linearize on a regular basis. There are at least two variables in the linearization process: the plate maker and the press itself. As you can imagine, it’s difficult to guarantee that press conditions are the same every day and on every sheet of paper. For this reason, most presses will linearize once or infrequently and depend on characterization.

Every device in the design to print workflow should be characterized. Cameras often have embedded ICC profiles that they will attach to images when they take them, but other devices need to have some measurements taken in order to get a profile. There are many different devices on the market to help produce an ICC profile. I am partial to Xrite’s family of devices, including the i1 and the Pulse. The Pulse is out of production now, but the i1 is current. These devices can make ICC profiles of monitors and printers, and provide very good results for representing color. These are not the only devices that do this, and I’ll leave it to the reader to explore more options for devices that can make ICC profiles.

Tube-based monitors used to go dim after a few years of continual usage. Also, the color would shift as the electron guns in the set would decay over time. Modern LCD monitors do not suffer from color degradation, but they do dim over time. In a working environment, it remains a best practice to set the monitor’s brightness to lower than maximum, so that you always have somewhere to go when the monitor begins to dim. Some shops measure their monitors daily. Others do is less frequently or once and forget it. I tried to adhere to at least monthly measurements, once I moved to LCD monitors. I would try to measure Tube monitors weekly.

We characterize a monitor by using a device like an i1 to measure how the monitor presents colors. The characterization process is a mixture of manual steps and automated steps. The manual steps might be steps like : set your monitor’s brightness and contrast settings to specific targets. Having done that, the machine can take over and make measurements. The user hangs the measuring device against the screen and the profiling software reads hundreds of color combinations directly off of the screen. Knowing the colors that the monitor does produce allows a profile to be created. The profile shows how the monitor responds to specific requests and allows your proofing software (Acrobat? Photoshop?) to accurately display color by using the profile.

Knowing how the monitor responds isn’t the end of the story.In addition, we need to ensure that the environment in which you will view electronic proofs also meets a standard. There are many schools of though on color viewing, but the IDEAlliance and IPA have been working on getting ISO standards for viewing conditions and lighting. Currently, there is no standard viewing condition, but a rule of thumb is neutral gray surroundings with shielding to prevent reflections off of the monitor.

Once we have all of our devices profiled, we can now begin using them for proofing. You need to think about proofing in the following way: I want to use my X to show how my document will look when output to Y. X is usually a desktop proofer like an inkjet printer or a monitor, and Y is usually a printing press. Of course, we can put any device whose characteristics I know (for which I have an ICC profile) in place of X and Y, but these are the most common.

Let’s look at the whole picture.

To proof a file electronically, you need to open it in an application that understands soft proofing. These include Photoshop, Illustrator, InDesign and Acrobat as well as some other applications. In Creative Suite, you need to tell the application what monitor you are using by ICC profile. Then, with your file open, you need to tell the application about the press and the proofer. The statement goes like this: I want to use my monitor to view how a file will print on a Heidelberg press with dull coated paper and the proof is printed on an Epson proofer with semigloss paper. Getting all of the menus chosen correctly varies between applications, but when done right, it’s a great workflow.

So, to answer the questions, yes, you should characterize your monitors at least monthly if they’re LCD and more frequently if they are tubes. You can do it yourself with an i1 or other device, but all the characterization in the world will do you no good if you don’t take into consideration the entire proofing workflow and get all the pieces in sync. If you have a consultant available, use them to help set up the applications for proper proofing and get everyone in your group on board with proper proofing practices.